针对一类具有随机干扰的多速率采样系统,本文建立了一种快速率故障检测方法.首先,应用提升和初等变换等技术将原有系统转换为线性时不变(LTI)且满足因果约束的慢速率系统;然后应用Kalman滤波设计出系统的慢速率稳态残差产生器;同时,为了克服上述残差产生器不能实时检测故障的缺陷,并考虑新系统中所增加的过程噪声与测量噪声之间、各测量噪声之间相关性等因素,基于序贯滤波的思想,进一步设计出能实时检测故障且能避免因果约束问题的快速率稳态残差产生器和残差评估方法;最后,用计算机仿真对所提方法的有效性进行了验证.

A fast rate fault detection method for a class of multirate sampled systems with stochastic disturbance is proposed.Firstly,with the aid of lifting and elementary transformation techniques,the original system is converted into a linear time-invariant (LTI) slow rate one satisfying causality constraint.Then a slow rate steady-state residual generator is designed based on the Kalman filter.Meanwhile,based on the idea of sequential filtering,a fast rate fault detection scheme consisting of a fast rate steady-state residual generation and the corresponding residual evaluation,which can avoid the troublesome causality constraint,is further developed to overcome the drawback to the above slow rate residual generator that it has a poor real time on fault detection.The auto-correlation of measurement noises and the cross-correlation of measurement noises and process noise increased in the new systems are also considered.Finally,simulation results illustrate the effectiveness of the proposed method.